The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
An aspect of invention firstly relates to a tensioning device for tensioning a flexible elongate member, such as a cord, comprising a first winding member which can rotate around an axle for, directly or indirectly, winding and unwinding the elongate member at a first end thereof, and a second winding member which can rotate around said axle for, directly or indirectly, tensioning the elongate member at the second end thereof, wherein the first and second winding members are interconnected by a tensioning member striving to cause a relative rotation between the first and second winding members for creating a prestress or tension in the elongate member.
For example such a tensioning device is applied in a sunscreen assembly, comprising a winding shaft which can rotate around an axle for winding and unwinding a sunscreen. A free end of the sunscreen remote from the winding shaft is engaged by a first end of the flexible elongate member which extends around a reversal roller and which has a second end that can be wound and unwound by a winding disk which can rotate around said axle. Here, the winding shaft defines the first winding member and the winding disk defines the second winding member of the tensioning device interconnected by, generally, a coil spring.
This known tensioning device, however, has the disadvantage that when the first end of the elongate member (in the above sunscreen assembly being attached to the sunscreen) is moved towards the first winding member (in the above sunscreen assembly that means when winding the sunscreen onto the winding shaft) too quickly, the inertia of the winding shaft may prevent the elongate member from being maintained in a taut state at its first end (in the above sunscreen assembly that means that the sunscreen is not kept taut), such that it will slack, resulting in an irregular winding thereof onto the first winding member (winding shaft). Moreover, when the first end of the elongate member (in the above sunscreen assembly being attached to the sunscreen) is moved away from the first winding member (in the above sunscreen assembly that means when winding off the sunscreen from the winding shaft) too quickly, the inertia of the second winding member (the winding disk of the sunscreen assembly) may prevent the elongate member from being maintained in a taut state, such that it will slack, resulting in a loss of function of the tensioning device.